Monday, January 30, 2012

Today in class we went over unit packet 13-16. Afterwards we started on our lab which is on pages 17A-17E.

The lab is called biochemical evidence for evolution. In the introduction it talks about the theory of evolution and how it is considered to be pivotal importance to modern biology, and how organisms change over time. It then talks about homologous structures which are structures that come from a common ancestor but have different functions. Specific examples are human, whale, cat, bird, and bat's bone. Also it talked about vestiges which are organs from our ancestral species but now are useless. An example is the appendix or coccyx. It later talks about embryology which shows evolutionary relationships between vastly different organisms. It helps show that early stages of development or organims are extremely similar.

Lab Procedures: We were supposed to get into groups of 4. We needed 5 testing well trays, 1 vial simulated human antiserum, 10 stirring picks, 3 plastic dropping pipettes, 1 vial of simulated human serum, 1 vial of simulated cow serum, 1 vial of simulated chimpanzee serum, 1 vial of simulated frog serum, 1 vial of simulated monkey serum water. We recieved five trays with 8 dents with them and supposed to label each dent 1-8. Each stimulated serum, recieved its own tray. Next we were supposed to place serum adn dilute it with water and then mix it.

The following numbers go by dent number, drops of serum, and drops of water

1:8:0

2-7-1

3-6-2-

4-5-3

5-4-4

6-3-5

7-2-6

8-1-7

Then we were supposed to put 8 drops os human antiserum and each dent adn mix it as well. We were supposed to wait two mintes to observe the reactions. We were supposed to observe if any agglutination occured and record it in the data table. It heavy agglutination occured then you should put down +++, for medium then ++, for slight then +, and for no then -.

On the picture on the top right is homologous structures, on teh left is examples of embroylogic developments for evolutionary realtionship, and on the right side bottom is picture of aggulunation in serum.

Thursday, January 26, 2012

Homework: Finish UP p. 5, 13-16, and 25-28. Also we are meeting in the auditorium tomorrow.

Due Today: UP p.19-20

In Class:

Today in class we went over UP p.19-20 about the who supported each theory; Darwin, Lamarack, both, or neither. These were the answers:

1. Darwin2. Darwin3. both

4. Lamarack5. Darwin6. Darwin

7. Darwin8. Lamarack9. Darwin

10. Darwin11. neither12. Darwin

13. Darwin14. Lamarack15. Lamarack

16. Darwin17. Darwin18. Lamarack

19. Darwin20. Neither21. Lamarack

22. Darwin23. Lamarack24. Darwin

25. Lamarack26. Darwin27. Lamarack

28. Darwin29. Darwin 30. Lamarack

*You do need to know Darwin and Lamarack's theories and how they were different for the test.

We also finished our notes from pages 15-16 where we learned about Natural Selection in Action. Some examples are:

Evolution of finches on Galapagos Islands: the islands were colonized by finches that strayed from the South American mainland.

Pesticides-do not create resistant individuals, but selects for resistant insects that were already present in the population.

2 populations of trees are separated by a river (particularly isolated from each other). Trees are more likely to breed with members of the same population on the same side of the river. Each side of trees could evolve different traits.

Next we did an in class lab on UP p. 25. In this lab we created an artificial environment to demonstrate the concept of natural selection. Are materials were:

A piece of patterned fabric (artificial environment)

10 different colors of construction paper

Petri dish

Our group used a zebra print cloth and this is the data we recorded:

Our group concluded that some traits help organisms adapt to their environment just like that dots had colors that camouflage them on the fabric. Therefore the dots/organisms that are best fit to that environment, survive.Next-VShow Jex

Wednesday, January 25, 2012

The notes that we took today were about Darwin, his theory, and some of the other biologists.

A few things to know about Darwin (1809-1882)

he introduced the theory that all life is connected

he was one of the most influential scientists in the development of modern biology

published the Origins of Species- there are two main points to his book- "decent with modification" or evolution, and natural selection

he became a naturalist at 22 for a voyage around the world on the ship the HMS Beagle

he was mainly in the Galapagos Islands

while of the voyage he collected many specimens and noticed that as the animals strayed from the mainland, they began to adapt

he also found that after many generations, two populations could slowly adapt and change so much so that they eventually became two different species

Darwin explained the adaptations through natural selection and had 3 main points- overproduction, variation, and reproductive success. He also looked at artificial selection and came to conclude that by modifying a species through breeding would end up with the offspring or flowers/vegetables not looking like their ancestors. Artificial selection is when the species is being selected for certain traits and combined to get the desired offspring.

Many scientists during Darwin's day thought that the earth was relatively young, and was full of unrelated species. A few of the scientists to know from his time are-

-Anaimander(Greek)- thought all life arose in water and simpler forms preceded the more complex ones

-Aristotle(Greek)- thought species did not evolve (static)

-Buffon (1700's french)- thought world was much older than 6000 years, and that a species in a fossil could be an ancient version of a living species

-Lamark (1800's french)- said life evolved through adaptation, but had a strange theory on how life evolved. He believed the "Inheritance of Acquired Characteristics" was how life evolved. So if you don't use a limb, then you will pass that on to your offspring and that offspring won't have that limb. So if you didn't ever use your thumb, then your child wouldn't have a thumb.

-Lyell (Scottish)- earth was old and he supported the gradualism principle

-Wallace (British)- developed idea of natural selection identical to Darwin's, but Darwin published his first, so Wallace isn't as well known

Examples that support evolution:

The fossil record- fossils can be used to research organisms from the past and are preserved in rocks. In the rocks, you can see different layers, and each layer is a different time period, as you dig further down, the fossils become older. Some of the oldest fossils are about 3.5 billion years old. The people who study these fossils are called paleontologists.

Biogeography- the geographic distributions of species. ex. the animals that are found in Australia are found almost exclusively in Australia because it's isolated by the ocean.

Comparative Anatomy- similar structure, but with different functions, and indicates that certain species came from a common ancestor (homology),vestigial organs or homologous structures can help trace back to a common ancestor, like in some animals such as the whale.

Comparative Embryology- comparison the organisms while they are developing

Molecular Biology- a common genetic code shared by organisms ex. there is less than a 2% difference in human and chimp DNA.

Review:Over production of offspring, individual variation, and differential reproductive success all lead to adaptive evolution.

Then type the video titles in the convenient little search box in the top- right corner of your screen, and find the link to the video. Note: You need quicktime to see the videos, and the subtitles are really useful!

Video 1: Isn't Evolution Just a Theory?

Question: Is it correct to say that evolution is JUST a theory?

Key Points:

Charles Darwin pioneered the idea that all life is connected, and the theory of natural selection

Theories pull together observations to create "rules" for how the universe works

Video 2: Who was Charles Darwin?

Question: Why was Darwin considered a "Revolutionary"

Key Points:

Darwin's work was highly controversial because it contradicted many established religious and scientific beliefs at the times

In order to prove his theories, he traveled the world and carefully documented life's great diversity, then analyzed the patterns

Video 3:How do we know that evolution happens?

Question:Describe the transitional fossils associated with whales.

Key Points:

The evolution of species can be plotted on an evolutionary timeline, which chronologically shows the changes ancient species went through in order to evolve into modern species

An ancient species that shares common traits with a modern one, and has no similar, discernable ancestors, may be the original ancestor to modern species

As time passes, the ancestor changes and adapts and become more similar to modern species

Video 4:L How does evolution really Work?

Question: Describe the process of natural selection and how it effects hummingbird populations.

Key points:

Genetic Variation: different individuals within a species express different traits, some more favorable than others

Overproduction of offspring: more offspring are produced than the number that can survive

Struggle for existence: The overload of individuals compete for resources

Differential survival and reproduction: Individuals without favorable traits are at a disadvantage for obtaining necessary resources. These individuals die. Those left have more favorable traits and have a higher chance of reproduction, so the favorable traits are inherited by the next generation.

Video 5: Did Humans Evolve?

Question: Explain how DNA sequences are used to provided eveidence of a commoon ancestor?

Key points:

Humans did not eveolve form chimapnzees, but both species shared a common ancestor

Humans and primates have similar DNA, which helps prove this relationship

If two species share the same gene sequences, aside from a few mutations, they are related

Question: Why is the theory of evolution an important theory for doctors and the field of medicine? How does the theory affect the way illnesses and treatments are approached?

Key Points:

Some microbes can evolve to become resistant to antibiotics, which is very dangerous

If one drug does not kill ALL of the microbes, the remaining resistant microbes reproduce and form an entire population of microbes resistant to a drug. Thus, they have evolved to evade our killing, which can result in difficult to cure diseases.

Tuesday, January 3, 2012

After we got back from winter break, we quickly dove into our next topic, THE MIRACLE OF LIFE!

We began the class by observing an immaculate movie on how different animals and species have sex. While we were watching the movie we were told to observe the different types of fertilization and developments that different organisms go through. The sheet that was supposed to be filled out on page 4 of the unit packet, touched on the requirements, advantages, disadvantages, and examples of both fertilization and sex. The chart below shows the answers. The picture above shows that you can not have sex with different species and not reproduce.

Since we are focusing on reproduction we need to know what reproduction means.

Reproduction: The creation of new individuals from existing ones

Sexual vs Asexual

Sexual is the creation of offspring by the fission of 2 haploid sex cells called gametes to form a diploid zygote.

Male gamete= Sperm

Female gamete= Egg

Advantages

Increases genetic diversity and a better way of survival throug sudden environmental changes

Asexual is the creation of offspring that are genetically identical to the parent

Examples include EXAMPLE OF SEXUAL REPRODUCTION ORGANISM

1. Bianary fission

2. Mitosis

3. Fission

4. Fragmentation

5. Regeneration

A Sexual reproduction Example would include your Mom and Dad because they ad to had sex to reproduce what is you today. By doing this your parents have increased the genetic diversity of the environment around you.

An asexual reproduction example would include Bianary fission between bacteria.

Some organisms can reproduce both sexually and asexually depending on environmental conditions.

Hermaphrodite: Equipped with both male and female reproductive systems. This would include a tapeworm because they can reproduce by themselves without any help.

Internal fertilization occurs when sperm are deposited in or near the female reproductive tract. This requires sexual intercourse.

External fertilization occurs when parents discharges gametes into water where the fertilization occurs.